B&W 803D crossover caps


I am considering an upgrade of the crossover capacitors in by B&W 803Ds, particularly the mid and HF coupling caps.

I took out the top bass driver to find out what caps were installed. It looks like for the diamond tweeter B&W uses a Mundorf Supreme silver/gold, 4.7 mfd 1200V. For the mid driver there are two; a 47 mfd Mundorf MKP 400V series coupling cap (in series with the driver) and a 10 mfd Mundorf Supreme siver/gold bypassing cap (parallel to the driver).

I was thinking about changing out all three, but have a few concerns.

I was going to replace the 10 mfd, 4.7 mfd Supreme silver/gold with Supreme silver/gold/oil. Would there be enough of a difference in these two types to justify the cost? I also do not want to make the upper end any brighter.

I am also concerned about the long term reliability of oil filled caps, as some failures have been reported in warmer environments. I wonder if B&W did not use the silver/gold/oils for that reason.

The biggest impact I suspect will come from the replacement of that series 47 mfd MKP. I would probably use either the Mundorf MCap EVO (Al metalization), MCap EVO oil (Al/oil), or the MCap EVO silver/gold/oil. All three are the same size for 47 mfd, and will fit to replace the MKP. Barring the issues about oil, which might be the best sounding? Again, I want to avoid too much enhancement of the upper midrange.
dhl93449

Showing 2 responses by mj1958werner

Hi guys,

I just took my midrange crossover out and replaced it with the midrange crossover of the 800D.
The bass and treble crossover are the same  in the 803D as in the 800D.
I owned the 800D years ago and always liked the sound of its midrange.
The sound wasn’t coming from the midrange but was like hanging around the speaker. (Maybe reversed polarity? )
I owned and tweaked lots of B&W speakers. The silver signature is one of my reference speakers and are recaped with mundorf silver gold in hi frequency and mundorf silver gold oil in midrange.
The sound is really transparent, lots of resolution, silky and no harshness. (Tweeter is also operating in reversed polarity here!)


There is some place in the bottem of the 803D cabinet.
Remove the bass crossover and install the 800D midrange crossover in theen same compartment, but upside down on the matrix internal structure.
Afterwards the 803D sounded
BEAUTIFUL.
The emphasis of the tweeter disappeared.
I wouldn’t put the silver oil, silvergold in oil in the tweeter or midrange because personal I found them to be a bit too detailed.
The 800D was the most natural sounding speaker of the whole 800D series. (800D, 800 Diamond )
The crossover cares 2× mundorf supreme and 1 silver gold (no oil).

Cheers Werner.


hi guys,

hope to open this archeologic thread back up 😁.
for the last 2 years i've been working on a couple of n803's.
guys have i been upgrading these speakers.
i rebuilded the crossovers from scrap.
hard wired on wooden multiplex boards.
the following brands have been used:

duelund vsf, cast cu, silver bypass for tweeter.

jupiter cu wax, mundorf  , jantzen foil inductors, path audio resistors for midrange.

mundorf bl 180 for bass and mkp for parallel.

matrix skeleton has been removed in the midrange compartment and a tube shaped room with a difuser has been installed.

a labyrinth has been installed between the matrix bass compartment to reduce standing waves.

original tweeter housing has been modified to accept diamond domes and therfore uses the 1st order crossover as seen in the "D" series.

the speaker cabinet was completely stripped, stained in red and sprayed in hi gloss with the polishing and stuff.

the tweeter housing as well the bass port are veneered in dark lambs leather.

as final all units have been finalized with chrome trim rings and bars as seen in the signature 30.

too bad i can't upload pictures but they are beautiful and sound awesome...

cheers,

werner